8.3.6 Device Reset Scenarios

There are three reset methods implemented on the :

• Software reset with SW_RESET register bit (in RESET register)
• POR from rising edge of NRST signal
• Undervoltage lockout (UVLO) reset from VANA supply

An SW reset occurs when SW_RESET bit is written 1. The bit is automatically cleared after writing. This event disables all the regulators immediately, resets all the register bits to the default values, and OTP bits are loaded (see Figure 21). I²C interface is not reset during software reset. The host must wait at least 1.2 ms after writing an SW reset until making a new I²C read or write to the device.

If VANA supply voltage falls below UVLO threshold level or NRST signal is set low then all the regulators are disabled immediately, and all the register bits are reset to the default values. When the VANA supply voltage rises above UVLO threshold level AND NRST signal rises above threshold level an internal POR occurs. OTP bits are loaded to the registers and a start-up is initiated according to the register settings. The host must wait at least 1.2 ms after POR until reading or writing to I²C interface.